Method for producing an elastic fabric



becyzo, 1938.

A. FERRARI METHOD FOR PRODUCING AN ELASTIC' FABRIC Filed Oct. 14, 1957 .jflnnlrg- Ferrari.

I r ven-tan Patented Dec. 20, 1938 UNITED STATES 2,140,696 METHOD FOR PRODUCING AN ELASTIC FABRIC Andi- Ferrari, Saint-Victor-sur-Rhins, France Application October 14, 1937, Serial No. 169,053 In France October 24, 1936 2 Claims.

The object of the invention is an elastic fabric intended for the manufacture of parachute surfaces.

It is' known that fabrics of natural silk, warp and weft woven at present used in the manufacture of parachute surfaces are not suitable when it is desired to equip high speed aircraft and when consequently the parachutes must be launched also with high velocities. The reason for th s is that the shocknpon opening, that is to say, the shock which is produced when the parachute unfolds and is suddenly stopped by the parachutist, is very great and often fatal for the latter, and that further the considerable stresses L supported by the fabric at this instant sometimes causes it to burst or produces tears and other accidents to the parachute.

Inorder to overcome'these disadvantages, it has already been proposed to use elastic fabrics, but the attempts which have hitherto been made have not given satisfactory results.

The object of the invention is to overcome the disadvantages hereinbefore mentioned while permitting an elastic fabric satisfying the actual requirements to be obtained, the elasticity of which 25 fabric distributes the stresses at the instant of the shock upon opening, said fabricstretching while playing the part of a damper and the napping of which is sufiicient to render it slightly permeable to air.

This fabric permits the manufacture of parachute surfaces capable of being used with aircraft travelling at 400 km. perhour, and producing upon opening and without any damage a shock which is not greater than that to which are 3 subjected the present parachute when travelling at 250 km. per hour.

It is constituted by a knitted warp fabric re--- sulting from the use in combination of different means which consist in the use of a warp knitting frame of a particular known type, and of a par-. ticular pattern or weave and texture, this combination giving a new industrial product, vim/the fabric forming the object of the invention. f}

45 With regard to the kind of frame, the latter is a warp knitting frame, gauge 26, with three guide bars.

With regard to the texture of the fabric, the latter is characterized by the feature that the 50 threads used are of natural raw silk, and that for the bars No. 1 and No. 3 the threads are with two ends and wound at about 350 turns per meter, whereas for the barNo. 2 the threads are with three ends with the same twist, each bar com- 5 prising about 2320 threads.

Finally, with regard to the weave given to the fabric, the latter is representedin the attached drawing and detailed as follows:-

Bar No. 1 Bar No. 2 Bar No. 3

1-0 3-4 1-0 6 3-4 l--ll ll-l I-0 3-4 I-ll 3-4 l-ll O-l As will be seen, the essential feature of this weave is that bars No. 1 and No. 2 are moved 10 lengthwise so as to give long and staggered displacements to the guides in order to produce the napping which has the consequence 'of rendering the fabric slightly permeable to air, while bar No. 3 moving according to ordinary meshing pattern has the effect of connecting together the threads of bars No. 1 and No. 2 and thus preventing any elasticity in width while permitting to the fabric full lengthwise elasticity.

After manufacture the, fabric is finished off in any suitable manner.

Obviously, in certain cases and without departing beyond the scope of the invention, certain modifications of detail may be introduced as nec- 'essary in the manufacture of this new elastic fabric such as for example in the number of guide bars and the gauge, or further in the number of threads, of ends or of turns or of slight modifications in the pattern.

I claim:

1. Process or method for producing an elastic fabric for parachute surfaces or sails on a warp knitting frame, with three guide bars, in which threads essentially of natural raw silk wound about 350 turns per meter, are distributed on each bar, the threads of bars Number 1 and Number 3 being with two ends whereas the threads of bar Number 2 are with three ends, which comprise moving the guide-bars lengt wise in such manner that bars Number 1 a d Number 2 are given long and staggered displacements while bar Number 3is' given short displacements.

2. Process or method for producing an elastic fabric for parachute surfaces or sails on a warp knitting frame, gauge 26 with three guide-bars comprising taking approximately 2320 threads of natural raw silk wound at about 350 turns per meter and distributing them on each bar in such manner that the threads of bars Number 1 and Number 3 have two ends whereas the threads of bar Number 2 have three ends and during weaving move the guide-bars lengthwise in such manner that bars Number 1 and Number 2 are given long and staggered displacements while her Number 3 is given short displacement.

ANDRNFERRARI. 

